Standardize how we refer to the kubernetes root.

Now use $KUBE_ROOT as the variable pretty much everywhere.

hack/test-go.sh

@@ -17,15 +17,15 @@
 
 set -e
 
-source $(dirname $0)/config-go.sh
+KUBE_ROOT=$(dirname "${BASH_SOURCE}")/..
+source "${KUBE_ROOT}/hack/config-go.sh"
 
 # Go to the top of the tree.
-cd "${KUBE_REPO_ROOT}"
+cd "${KUBE_ROOT}"
 
 # Check for `go` binary and set ${GOPATH}.
 kube::setup_go_environment
 
-
 find_test_dirs() {
   cd src/${KUBE_GO_PACKAGE}
   find . -not \( \